Abstract
Abstract: :
Purpose: Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in people over 65. Severe loss of vision occurs in exudative AMD with the development of choroidal neovascularization (CNV). We injected Matrigel into the subretinal space in rats to form a subretinal deposit which functionally mimics important aspects of basal linear deposit and/or soft drusen. Methods: Eyes of adult Sprague-Dawley rats were injected with 2-3 µl of Matrigel to the subretinal space through a 33-gauge needle connected to a 10 µl Hamilton microsyringe. A week or more later, animals were sacrificed by CO2 inhalation and perfused with Vessel Paint, a solution contains DiI, followed by 4% paraformaldehyde solution. The anterior portion of the eye, including the cornea and the lens, was removed and the eyecup embedded in 5% agarose. Serial thick sections (100 µm) of the eye were cut on a vibratome and mounted on glass slides. Eye sections were examined by fluorescence microscopy for neovascularization in the Matrigel deposit. Serial optical sections were obtained using confocal microscopy. Three-dimensional reconstruction of newly developed blood vessels was achieved using Auto Visualiz-3D (AutoQuant Imaging, Inc). Protein leakage of the new vessels was detected by assessing color change in the Matrigel deposit after i.v. injection of Evan's Blue dye. Results: Neovascularization was observed as early as 7 days after Matrigel injection. Newly developed vessels formed a extensive network 14 days after Matrigel injection. Three-dimensional reconstruction clearly shows that the new vessels originated from the choroid. Matrigel deposit became light blue in color after Evan's Blue injection, compared with pale white in surrounding tissue, indicating the lack of barrier characteristic. Discform scar was observed 30 days after Matrigel injection. Conclusion: Subretinal Matrigel deposits induce CNV in the subretinal space, mimicking the pathology seen in exudative AMD. It provides an improved animal model for research of the pathology of CNV and for testing potential therapies.
Keywords: 346 choroid: neovascularization • 308 age-related macular degeneration • 316 animal model